This invention relates to a truss construction useful as roof or floor joist supports in building constructions. The type of truss involved is formed of metal chords interconnected by metal webs to provide a prefabricated, elongated truss.
Trusses formed of metal chords and metal interconnecting webs are known. However, available devices are relatively expensive and are difficult and expensive to fabricate. Hence, trusses made out of a combination of wood chords with metal connector webs have been developed in an effort to reduce costs and provide necessary strengths. Examples of this kind of construction are illustrated in my prior U.S. Pat. No. 4,002,116, issued Jan. 11, 1977, and entitled "Apparatus for Forming Trusses" and also in my prior U.S. Pat. No. 4,078,352, issued Mar. 14, 1978, and entitled "Truss-Web Connector".
In my prior patents, the chords are formed of elongated wood strips which are interconnected by pre-formed sheet metal webs whose opposite ends overlap the sides of the chords and are fastened thereto by means of struck-out teeth embedded into the wood. Preferably, the webs are formed in V-shaped groups of two which provide a zig-zag interconnection along the length of the truss. With that kind of truss, the connector plates are arranged to overlap the wood chords. That is, their toothed connector portions overlap the wood and by means of a suitable apparatus, such as that illustrated in my U.S. Pat. No. 4,002,116, mentioned above, the connectors are forced into interlocking engagement with the wood chords.
The foregoing type of truss and method of fabricating and equipment produce an economical, highly satisfactory, strong truss for use as a joist. However, for certain purposes, it is desirable to use a metal chord construction, particularly in view of the growing unavailability and rising costs of good lumber from which the chords may be made. Thus, the invention herein is concerned with producing a good, inexpensive, truss or joist utilizing metal chords so as to avoid the necessity of using expensive, high quality chord lumber, but still including some wood chord parts.